1. Field of the Invention
The present invention relates to an exhaust gas purification device and a control method thereof. More particularly, the present invention relates to an exhaust gas purification device that can supply a gasoline particulate filter with enough oxygen to regenerate it and a control method thereof.
2. Description of Related Art
Generally, a gasoline direct injection (GDI) art has been developed so as to improve fuel consumption efficiency and performance of an internal combustion engine, wherein the GDI engine does not inject fuel into an intake pipe, but direct injects the fuel into a combustion chamber.
Since the air/fuel ratio is low (dense fuel) around a spark plug, an engine is operated in a lean fuel condition, but there is a problem that a gasoline direct injection engine (GDI) generates a large amount of particulate matter (PM) according to an incomplete combustion period increment in a combustion chamber.
It is necessary to correspond to PM exhaust regulations and PM nanoparticle amount regulations for a GDI engine equipped vehicle of the EURO 6 standards. For this, research into applying a particulate filter that is used for a diesel engine to a gasoline engine to correspond to the emission regulations has been developed.
However, because the gasoline engine is operated at an ideal air/fuel ratio, there is not sufficient oxygen for burning PM that is trapped in the gasoline particulate filter, regenerating the filter is difficult, and long regeneration time is necessary.
In a conventional art, a device for supplying a particulate filter with oxygen to resolve the above problem is used.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.